PVC is mixed with appropriate additives in a certain proportion, generally using a "Z" kneading machine or high-speed kneading machine to make it mix evenly, and then granulating by an extruder or using twin screw powder to form at one time. The speed of the single screw extruder is generally 30~60r/min, and the pressure control of the head is about 36~54MPa. The material should be fully plasticized and freely blown into bubbles with compressed air. After the extrusion is stable, the corrugated molding device and the extrusion outlet die are inserted, and the center line of the two is aligned, and the distance in the extrusion mold should be greater than the distance of a pair of molding modules to ensure that the upper and lower modules are fully closed before forming the product. The corrugated forming device is composed of a forming mold, a transmission system and a control system, which not only plays the role of product forming, but also plays the role of traction. The ring grooves of the upper and lower forming molds must be aligned and should not be misaligned. The traction speed is generally controlled at about 6~10m/min. The blowing pressure is based on the principle of complete blowing of the annular groove of the product, which generally requires 0.15MPa. The mold temperature is controlled at about 45~60°C to facilitate the basic shaping of the product before mold opening and avoid the elongation of the corrugated pitch during winding.
Extrusion temperature control 145~160°C in the feeding section, 165~175°C in the compression section, 175~185°C in the metering section, 175°C~180°C in the machine head, and 170~180°C in the mouth mold.
